Marks and Spencer’s (M&S) market value has dropped by almost £700m as it instructs its warehouse staff to stay at home, following its ongoing cyber crisis.

The high street retailer has seen its shares fall almost 7% since last Tuesday (22 April) when it first announced its IT systems had been breached by a cyber attack that left customers unable to pay for their shopping.

According to The Financial Times, the fallout from its IT disruption has caused the FTSE 100 retailer’s market value to drop by £678m in this period.

This morning (28 April), it was revealed that M&S had ordered hundreds of agency workers from its main distribution centre to stay at home.

The almost 200 employees who were due to take on shift work at its East Midlands Castle Donington clothing and homewares logistics centre were instructed not to show up, reported Sky News.

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Meanwhile, work-from-home staff have been blocked from using internal systems remotely, as it tightens up IT security amid fallout from an ongoing cyber attack.

Elsewhere, customers are also still facing the impact of the ransomware attack, as the retailer was forced to resort to pen and paper for its Sparks loyalty card transactions.

In its last public update on Friday (25 April), the company announced it had halted orders via the M&S.com websites and app. It added it was working with external cyber experts to restate online and app shopping.

The statement said: “We informed customers on Tuesday that there was no need for them to take any action. That remains the case, and if the situation changes we will let them know.”